#include <iostream>
#include <iomanip>
using namespace std;

int main(){
	int n,g,s;
	cin>>n;
	cout<<fixed<<setprecision(1)<<(n/10)*1.0/(n%10);
}


/**************************************************************
	Problem: 1607
	User: admin
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/